Telecommunication networks critically depend on charging operations, for technical and economic reasons. Online charging conditions the usage or “consumption” of a communication service by a particular user, based on making corresponding “reservations” against a subscriber account to be charged for the usage. Initiating or continuing a communication session in the context of online charging, therefore, involves a series accounting messages flowing between a charging client associated with control of the session and a charging server associated with assessing charges against the subscriber account.
In an example scenario, a request for web or other data access causes a Charging Trigger Function (CTF) to communicate with an Online Charging Function (OCF). Here, the CTF operates as the charging client and it sends a reservation request to the OCF operating as the charging server. When granting a reservation request for particular user, the OCF makes a reservation against the associated subscriber account, meaning that all or a portion of the credit balance in the subscriber account is reserved for consumption of the resource quota granted for consumption by the user. Resource quotas may be expressed in terms of the underlying communication resource, e.g., in bytes of data, minutes of connectivity, etc., and a rating function may be used to translate the quota units into a monetary value, to be “locked” or reserved in the subscriber account.
Further reservations support continuation of the communication session beyond the extent permitted by the initial quota reservation, and termination of the communication session triggers reconciliation of the consumption data, release of any reserved units or funds, etc. Extensive example details in the context of DIAMETER-based charging appear in the Third Generation Partnership Project (3GPP) technical specification that is entitled “Telecommunication management; Charging management; Diameter charging applications,” and identified as TS 32.299.
Charging operations involve significant signaling going between the charging clients and the supporting charging server(s), and impose potentially significant processing burdens on the respective nodes, in terms of computational and working storage requirements. Competing interests and established protocols complicate the optimization of charging operations with respect to the signaling overhead and processing burden.
For example, making a quota reservation against a subscriber account ties up at least a portion of the funds available in the subscriber account, which may result in the account being considered deficient with respect to authorizing other services during the time that the quota reservation is considered valid. These account “impairments” militate against making overly aggressive quota reservations. Here, larger or longer lived quota reservations are considered more aggressive than smaller or shorter lived quota reservations.
On the other hand, more aggressive quota reservations tend to reduce signaling overhead, because new or refreshed reservations are needed less frequently with respect to the involved communication sessions. Conversely, when quota reservations are less aggressive, new reservations generally need to be made more frequently, because less aggress reservations have shorter timer values and/or provide for less consumption than would a more aggressive reservation. Advantageously, however, using shorter, less aggressive timer values tends to reduce the overall number of active reservations that need to be supported at the involved nodes.
Recognized herein is the fact that “standard” approaches to reserving quota does not accommodate the fact that operating conditions at the requesting client may diverge from conditions at the supporting server. Thus, such as seen in TS 32.299, having the server control the resource reservation parameters denies charging clients the opportunity to “tune” requested reservations to their operating conditions.